1. Field of the Invention
The present invention relates to an apparatus for mobile communications, and more particularly to an apparatus and a method usable with a plurality of communications systems.
2. Description of the Related Art
At present, there are a variety of communications systems in use, differing with geographical area and application among other factors. For instance, there are the second generation personal handy phone system (PHS) and cordless systems, which are relatively inexpensive by virtue of the simplicity of network but do not warrant communication capability when in high speed transit. On the other hand, there are mobile telephone and cellular systems which do warrant communication capability in fast transit by virtue of steps taken against such disturbing factors as hand-over and fading though involving relatively high communication costs. Furthermore, there are pager systems allowing only reception while in transit.
Each of these many communications systems has its own hardware, such as PHS terminals and portable telephones.
However, with a view to enhancing the convenience of the users of such mobile wireless terminals, there are proposed portable wireless terminals which permit connection to a plurality of communication systems with a single unit.
It is considered preferable, in view of the cost of communication, for such a portable wireless terminal connectable to a plurality of communication systems, e.g. a cordless system and a cellular system, to preferentially access the cordless system. If access to the cordless system is given priority, even when the terminal is in a fast moving body, such as an automobile, access will be made to the cordless system which intrinsically does not warrant communication capability. In this case, when the bearer of the terminal has just got on the automobile, or the vehicle is waiting for a green light or running at a low enough speed not to affect communication, there will be no problem, but it is unrealistic to expect the vehicle to be always running so slowly or at halt. Therefore, if the bearer, while riding a vehicle, stands by or initiates a call via the cordless system, the conversation may be interrupted when the vehicle accelerates beyond a certain speed.
An object of the present invention is to solve the above-described problem, and to provide an improved apparatus for mobile communications.
Another object of the invention is to provide an apparatus for mobile communications capable of automatically accessing the most suitable system for intended communication.
Still another object of the invention is to provide an apparatus for mobile communications capable of perceiving for itself, when it is used in a mobile object such as an automobile, its presence in a mobile object, and automatically forbidding access to any communication system unsuitable for communication during high speed transit.
In order to achieve the above-stated objects, according to the invention, there is provided an apparatus for mobile communications comprising a plurality of radio communication sections capable of communicating with a plurality of communication systems, and a control section for selecting and using one of the plurality of radio communication sections, wherein the control section judges whether or not communication during high speed transit is possible and, if it is possible, gives priority to a radio communication section communicating with a system appropriate for communication during high speed transit, and forbids a radio communication section communicating with a system inappropriate for communication during high speed transit from standing by or initiating a call.
The control section should preferably judge the possibility of communication during high speed transit according to whether or not the apparatus is to be used in an automobile.
The control section can judge the possibility of communication during high speed transit by the presence or absence of connection to a car adapter or a car battery.
It is further preferable for the apparatus to have a notifying section for issuing an alarm to its user if the control section detects the possibility of communication during high speed transit when communication is being accomplished by a radio communication section unsuitable for communication during high speed transit.
It is desirable for the control section to automatically process call release after the alarm section has issued an alarm.
According to the invention, there is also provided an apparatus for mobile communications comprising a first radio communication section capable of communication during high speed transit; a second radio communication section incapable of communication during high speed transit; a control section for selecting and using either the first or the second radio communication section; and a judging section for judging whether or not communication during high speed transit is possible; wherein the control section, if the judging section judges communication during high speed transit is possible, gives priority to the first radio communication section by forbidding the second radio communication section from standing by or initiating a call.
An alarm should preferably be issued if the judging section detects the possibility of communication during high speed transit when communication is being accomplished by the second radio communication section.
After the power supply is turned on, if the judging section finds the possibility of communication during high speed transit, preferably the first radio communication section should be caused to stand by, or if the judging sections finds no possibility of communication during high speed transit, preferably both the first and the second radio communication sections should be caused to stand by.
When the judging section finds the possibility of communication during high speed transit after an action to initiate a call or during conversation, if the second radio communication section is selected, an alarm should desirably be issued or, if the first radio communication section is selected, no alarm should desirably be issued.
Judgment of the possibility of communication during high speed transit by the judging section should preferably be accomplished according to whether or not the apparatus is connected to a car adapter or a car battery.